91920155497 has 2 divisors, whose sum is σ = 91920155498. Its totient is φ = 91920155496.

The previous prime is 91920155443. The next prime is 91920155519. The reversal of 91920155497 is 79455102919.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48143381056 + 43776774441 = 219416^2 + 209229^2 .

It is a cyclic number.

It is not a de Polignac number, because 91920155497 - 2¹⁵ = 91920122729 is a prime.

It is not a weakly prime, because it can be changed into another prime (91920155597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45960077748 + 45960077749.

It is an arithmetic number, because the mean of its divisors is an integer number (45960077749).

Almost surely, 2^91920155497 is an apocalyptic number.

It is an amenable number.

91920155497 is a deficient number, since it is larger than the sum of its proper divisors (1).

91920155497 is an equidigital number, since it uses as much as digits as its factorization.

91920155497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1020600, while the sum is 52.

The spelling of 91920155497 in words is "ninety-one billion, nine hundred twenty million, one hundred fifty-five thousand, four hundred ninety-seven".